Carbon Cycle Tracers Infographic - Meredith Lab€¦ · Carbon Cycle Tracers other natural...
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Solution: Use gases that share common mechanisms with CO 2 fluxes as carbon cycle tracers. For example, COS and 18 O-CO 2 share common leaf-level mechanisms with photosynthesis. COS CO 2 H 2 O 18 O-CO 2 18 O-H 2 O CO 2 18 O-CO 2 o 18 O COS Soil uptake Leaf uptake Photosynthesis Leaf water Ecosystem scale fluxes of CO 2 and carbon cycle tracers Soil microbial community Autotrophic respiration Soil respiration Leaf exchange Soil exchange o 18 O Soil water Photosynthesis Respiration CO 2 Carbonic anhydrase diversity and distribution in microbes Carbonic anhydrase classes: α, β, γ, δ, ζ, η CO 2 Understanding the role of Carbon Cycle Tracers within our soils and how they function along side other natural components within our ecosystems. Carbon Cycle Tracers Soil 2,300 Surface ocean 1,000 Deep ocean 37,000 Reactive sediments 37,000 Fossil fuels Plant respiration Microbial respiration Air-sea gas exchange Photosynthesis 9 Fossil 10,000 60 60 90 3+120 2+90 Atmosphere 800 COS H 2 O H 2 O H + + + CO 2 CO 2 H 2 S HCO 3 - + H 2 O 18 O-CO 2 + CO 2 18 O-H 2 O + + Chloroplast Carbonic anhydrase enzyme Carbon cycle tracers share a common diffusion pathway with CO 2 during photosynthesis. Gases diffuse from the atmosphere through leaf stomata into the mesophyll cells where the biochemistry happens. Fluxes of CO 2 would be measured alongside fluxes of one or both carbon cycle tracers to constrain the amount of photosynthesis in the ecosystem. The net flux of CO 2 could then be partitioned to separately study photosynthesis from respiration including respiration from the plant itself (autotrophic) and fromsoil microbes). However, the carbon cycle tracers COS and 18 O-CO 2 have been observed to have soil fluxes (orange arrows), which complicate their use as carbon cycle tracers (no longer specific just for leaf-level mechanisms). New research on soil fluxes of carbon cycle tracers is needed to account for these processes. It is likely that carbonic anhydrase enzymes in soil microbes drives the observed soil-level fluxes as it did the leaf-level fluxes. Microbes are known to encode for 6 different classes of carbonic anhydrase. This is an active area of study that is critical to the future of these carbon cycle tracers to help constrain the response of the terrestrial biosphere to global change. References by Laura Meredith, PhD | Associate Research Scientist University of Arizona, Saleska Lab Ecology & Evolutionary Biology Graphics by Luke Williams and Melissa Yepiz | Undergraduate Studies University of Arizona School of Art Problem: Photosynthesis and respiration drive large and opposing fluxes of CO 2 that are difficult to resolve at the ecosystem and global level. CO 2 and the carbon cycle tracers then share a common biochemical path by reacting with the same carbonic anhydrase enzyme. Photosynthesis: CO 2 taken up by the plant: [ 6CO 2 + 6H 2 O → C 6 H 12 O 6 +6O 2 ] CO 2 is also released by the plant, the bark, its roots and the microbes growing within the soil. Changes in CO 2 concentration could arise from changes in photosynthesis, or respiration, or both, making it difficult to interpret observations of the net flux. light [ C 6 H 12 O 6 + 6O 2 → 6CO 2 +6H 2 O ] Net flux = Photosynthesis + Respiration At a global scale, we have the same problem. How do we tell how much CO 2 is taken up by photosynthesis versus respired by terestial biosphere? Carbonic anhydrase Structure: O=C=O Abundance: 400 parts per million (400 molecules of CO 2 out of 1,000,000 molecules of air) and rising. Key features: The building block of life on Earth, most important greenhouse gas to climate change. Carbon Dioxide, CO 2 Carbonyl sulfide, COS or OCS Structure: O=C=S Abundance: 500 parts per trillion (500 molecules of COS out of 1,000,000,000,000 molecules of air) Key features: Taken up by plants during photosynthesis, most abundant sulfur-containing gas in the atmosphere. Oxygen isotopes of carbon dioxide, 18 O-CO 2 and 16 O-CO 2 Structure: 18 O= 12 C= 16 O and 16 O= 12 C= 16 O Abundance: Most oxygen in the atmosphere is 16 O (99.8%), but a small portion (0.2%) is stable 18 O that has two additional neutrons. Key features: Oxygen isotopes of CO 2 affected by photosynthesis, an important tracer for carbon and water cycles. The ability to separately measure and study photosynthesis and respiration is critical as they are the largest fluxes in the carbon cycle. Even small differences in the balance between terrestrial photosynthesis and respiration will strongly affect the fate of the large soil carbon stores and thus climate feedbacks Carbon Global Cycle
Transcript of Carbon Cycle Tracers Infographic - Meredith Lab€¦ · Carbon Cycle Tracers other natural...
Solution: Use gases that share common mechanisms with CO2 fluxes as carbon cycle tracers. For example, COS and 18O-CO
2 share
common leaf-level mechanisms with photosynthesis.
COS CO2 H
2O 18O-CO
2
18O-H2O CO
2
18O-CO2
o18O
COS
Soil uptake
Leaf uptakePhotosynthesis
Leaf water
Ecosystem scale fluxes of CO2 and carbon cycle tracers
Soil microbial community
Autotrophicrespiration
Soil respiration
Leafexchange
Soil exchange
o18OSoil water
Photosynthesis
RespirationCO2
Carbonic anhydrase diversity and distribution in microbes
Carbonic anhydrase classes: α, β, γ, δ, ζ, η
CO2
Understanding the role of Carbon Cycle Tracers within our soils and how they function along side other natural components within our ecosystems.Carbon Cycle Tracers
Soil2,300
Surface ocean1,000
Deep ocean37,000
Reactive sediments37,000
Fossil fuels
Plantrespiration
Microbialrespiration
Air-sea gasexchange
Photosynthesis
9
Fossil10,000
60
6090
3+120
2+90
Atmosphere800
COS
H2O
H2O
H+
++
CO2
CO2
H2S
HCO3
-
+H
2O
18O-CO2
+
CO2
18O-H2O
+
+
Chloroplast
Carbonic anhydrase enzyme
Carbon cycle tracers share a common diffusion pathway with CO
2 during photosynthesis. Gases diffuse
from the atmosphere through leaf stomata into the mesophyll cells where the biochemistry happens.
Fluxes of CO2 would be measured alongside fluxes of one or both carbon cycle tracers to
constrain the amount of photosynthesis in the ecosystem. The net flux of CO2 could then be
partitioned to separately study photosynthesis from respiration including respiration from the plant itself (autotrophic) and fromsoil microbes). However, the carbon cycle tracers COS and 18O-CO
2 have been observed to have soil fluxes (orange arrows), which complicate their use
as carbon cycle tracers (no longer specific just for leaf-level mechanisms).
New research on soil fluxes of carbon cycle tracers is needed to account for these processes. It is likely that carbonic anhydrase enzymes in soil microbes drives the observed soil-level fluxes as it did the leaf-level fluxes.
Microbes are known to encode for 6 different classes of carbonic anhydrase. This is an active area of study that is critical to the future of these carbon cycle tracers to help constrain the response of the terrestrial biosphere to global change.
References by Laura Meredith, PhD | Associate Research ScientistUniversity of Arizona, Saleska Lab Ecology & Evolutionary Biology
Graphics by Luke Williams and Melissa Yepiz | Undergraduate Studies University of Arizona School of Art
Problem: Photosynthesis and respiration drive large and opposing fluxes of CO2 that are difficult to resolve at the
ecosystem and global level.
CO2 and the carbon
cycle tracers then share a common
biochemical path by reacting with the same
carbonic anhydrase enzyme.
Photosynthesis: CO
2 taken up by the plant:
[ 6CO2+ 6H
2O → C
6H
12O
6+6O
2 ]
CO2 is also released by the plant,
the bark, its roots and the microbes growing within the soil.
Changes in CO2 concentration could
arise from changes in photosynthesis, or respiration, or both, making it difficult to interpret observations of the net flux.
light
[ C6H
12O
6+ 6O
2→ 6CO
2+6H
2O ]
Net flux = Photosynthesis + Respiration
At a global scale, we have the same problem. How do we tell how much CO
2 is taken up by
photosynthesis versus respired by terestial biosphere?
Carbonic anhydrase
Structure: O=C=O
Abundance: 400 parts per million (400 molecules of CO
2 out of 1,000,000 molecules
of air) and rising.
Key features: The building block of life on Earth, most important greenhouse gas to climate change.
Carbon Dioxide, CO2
Carbonyl sulfide, COS or OCSStructure: O=C=S
Abundance: 500 parts per trillion (500 molecules of COS out of 1,000,000,000,000 molecules of air)
Key features: Taken up by plants during photosynthesis, most abundant sulfur-containing gas in the atmosphere.
Oxygen isotopes of carbon dioxide,
18O-CO2 and 16O-CO
2
Structure: 18O=12C=16O and 16O=12C=16O
Abundance: Most oxygen in the atmosphere is 16O
(99.8%), but a small portion (0.2%) is stable 18O
that has two additional neutrons.
Key features: Oxygen isotopes of CO2 affected by
photosynthesis, an important tracer for carbon
and water cycles.
The ability to separately measure and study photosynthesis and respiration is critical as they are the largest fluxes in the carbon cycle. Even small differences in the balance between terrestrial photosynthesis and respiration will strongly affect the fate of the large soil carbon stores and thus climate feedbacks
Carbon Global Cycle
